#### # # ##### ##### # # # # # # # # # # # # # # # # # # # ## # # # ##### # # ## ## # # # #### # # ##### # HISTORY OF CHANGES 1.1.01 OSCAT Wind Data Processor (OWDP) Version 1.1 25 February 2013 This documentation was developed within the context of the EUMETSAT Satellite Application Facility on Numerical Weather Prediction (NWP SAF), under the Cooperation Agreement dated 29 June, 2011, between EUMETSAT and the Met Office, UK, by one or more partners within the NWP SAF. The partners in the NWP SAF are the Met Office, ECMWF, KNMI and Meteo France. Copyright 2013, EUMETSAT, All Rights Reserved. CHANGE RECORD Version Date Author/changed by Remarks --------------------------------------------------------------- 1.0.01 20-12-2011 Anton Verhoef First draft, for OWDP 1.0 beta release 1.1.00 06-02-2013 Anton Verhoef Version for OWDP 1.1 public release 1.1.01 25-02-2013 Anton Verhoef DRI comments incorporated --------------------------------------------------------------- Changes in OWDP v1.1.00 06 February 2013 - Skip the fractional part of second in the level 2a time field rather than rounding it to the nearest integer, to avoid value of 60 seconds. - Implemented GRIB API library version 1.9.18. - Limit brightness temperatures to BUFR output limitations to prevent write errors. - Re-compute Oceansat-2 orbit numbers based on generic orbit information since HDF5 values are not always exact. - Limit the maximum value of ambig%error_dir to 327.66 rather than 327.67 to prevent encoding of MLE values as 'missing' in BUFR output. - Several improvements to owdp_icemodel. The initial version was a copy of the ice screening routines for SeaWinds and ASCAT and not thoroughly tested with OSCAT data. Comparison of OSCAT ice maps with ASCAT ice maps lead to several modifications. Changes in OWDP v1.0.03 15 October 2012 - Tuned QC threshold (wind speed dependent parabole denoting maximum MLE value). - Implemented product monitoring based on statistics of average MLE, number of KNMI flags set and O vs. B wind speed difference. - In the land screening, use a smaller radius around cell to look for land mask grid points for 25-km product: 50 km vs. 80 km in the 50-km product. - Set Sigma0 Quality Flag for beams with a Kp(A) value of above 1.013 (1.3%) in order to exclude those WVCs from inversion. This happens when very few slides contribute to the WVC sigma0. - Implemented '-allswath' option to compute wind data in the outer swath where only VV-polarised data are available. - Apply some corrections for sigma0 values close to zero in ISRO v1.3: apply small linear sigma0 correction on inner beam and skip cells with negative WVC sigma0s. - Increased maxnr_of_grib_messages from 350 to 400 to keep compatibility with NCEP model. - Replaced unused WVC quality flag 'reserved' by 'morethan_2_vv' flag to indicate presence of more than two beams containing VV-polarised data. - Introduced NSCAT-3 GMF with wind speed scaling above 15m/s. NSCAT-2 wind speed of 30 m/s is reduced to 25 m/s in NSCAT-3. - Implemented new ASCAT-like output file naming convention containing sensing start time and grid spacing. - Implemented latitude-dependent sigma0 correction to correct negative wind speed biases on the southern hemisphere. - Replace exact comparison with missing_real by check on greater than missing_real*0.99 in ice model. - Distinguish between fore and aft beams based on satellite direction of motion when reading L2A HDF5 files. Changes in OWDP v1.0.02 17 January 2012 - Retrieve beam polarisation from sigma0 qual flag, not from beam number. - Correct incidental wrong beam assignments in L2A product by comparing slice azimuth numbers with the inner/outer beam average azimuth numbers. - Skip the atmospheric attenuation computation in mononly or properties modes. Changes in OWDP v1.0.01 20 December 2011 - Several changes to read the newer HDF5 L2A files from ISRO and NOAA (25 km). - Apply atmospheric attenuations from a climatological lookup table. The table and algorithm are based on software which was kindly provided by NOAA. The sigma0 calibration correction of +1dB that is applied with the -calval option is reduced to +0.65 dB. - Determine the time interval between subsequent NWP forecasts automatically. The interval was fixed to 3 hours but is now dynamically assigned. - Store the ISRO software version in the nof rain index field in order to preserve this information also in the BUFR data. - Apply sigma0 bias correction dependend on ISRO data version (although correction is the same now for all versions). - Some more changes to handle ISRO processor version 1.3. The linear sigma0 corrections (associated with the noise subtraction problem) are not necessary any more for this version. Changes in OWDP v0.2.00 18 August 2011 - Apply a linear sigma0 correction for problems with the noise subtraction in the L2A products.